Superficial venous thrombosis (SVT) is a common inflammatory and thrombotic pathology occurring within a superficial vein. SVT can result in distressing symptoms of redness and pain in the affected area and exposes patients to a risk of developing deep vein thrombosis (DVT) and pulmonary embolism (PE). Various therapeutic options are available to patients including anti-inflammatories, anti-coagulation and surgical procedures, however which of these therapies is the best first line treatment remains unknown. Several randomized controlled trials have been conducted addressing this question, yet methodological and design flaws have limited the translation of their results into a change of clinical practice. The following thesis consists of a multi-step process of reviewing the evidence to date followed by a process of engaging with clinician stakeholders with the goal of designing a randomized control trial that would provide a meaningful answer to patients and their clinicians. In the first step of this process, a systematic review of the literature was performed, including a meta-analysis to estimate pooled risk of developing symptomatic venous thromboembolic (VTE) complications in patients with isolated SVT following various treatments. These results were then presented to expert Canadian clinicians in a series of surveys using a Delphi process to determine the clinical trial design that would have the greatest impact on changing clinical practice. An additional survey of expert clinicians was conducted to determine current practice variation in the diagnosis, management, and follow up of patients with SVT, in order to design a clinical trial that best reflected current standard Canadian clinical practice.
Our systematic review identified 15 articles and including 5775 patients. Quality and assessment of risk of bias was moderate for most included studies. The findings of our meta-analysis identified that Fondaparinux, at prophylactic dose, to had the lowest event rate of 2.0 events per 100 patient years of follow-up (95% CI 0.4 to 4.7, I2=33%) for the primary outcome of deep vein thrombosis (DVT) or pulmonary embolism (PE) during follow-up. Pooled event rates ranged from 8.6-16.6 events per 100 patient-years across other treatment categories, including placebo/observation only, with an event rate of 10.5 events per 100-patient years (95% CI 3.0 to 22.0). Heterogeneity was moderate to high for most pooled estimates, limiting the interpretation of these findings.
Our survey of practice variation among expert Canadian clinicians revealed wide practice variation in in diagnosis and therapeutic management including sub-groups (e.g. cancer). There was agreement that clinical equipoise exists for the optimal treatment of SVT (77% of respondents), supporting the need for further research. Two rounds of surveys were performed using Delphi process methods, resulting in consensus for the design of a future randomized control trial (RCT). The agreed on design was for a randomized control trial comparing a direct oral anticoagulant (DOAC) such as Rivaroxaban, to Non-Steroidal Anti-Inflammatories (NSAIDs), using a non-inferiority RCT design with a non-inferiority margin of 3%.
Future direction of this research will be to continue stakeholder engagement by engaging patients in the clinical trial design, followed by development of a pilot RCT protocol and application for peer-reviewed funding.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/37105 |
| Date | January 2018 |
| Creators | Duffett, Lisa |
| Contributors | Carrier, Marc |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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